摘要
为了提高深井、超深井上部大尺寸井眼的钻井速度,常采用小钻头先钻一个井眼后再下入扩眼钻头扩眼的办法,由于改进牙轮钻头的难度较大。而PDC钻头在钻进软到中硬地层时具有钻速高、寿命长的特点,为此,在对深井大尺寸井眼的钻井特点、先钻后扩的破岩机理进行研究的基础上,研制了新型PDC扩眼钻头——PD6352SF- 311．1×444．5扩眼钻头。该扩眼钻头在DB1井φ444．5 mm井眼的平均机械钻速为21．68 m／h,与邻井莱深1井和郝科1井相比,分别提高了5．2％和38．0％,而且钻头起出后新度达80％,还可继续使用,从而进一步降低了钻井成本。
The method commonly used to improve drilling speed in upper large size wellbore of deep and ultra-deep wells is to drill a pilot hole with a small size bit at first and then ream it to a normal size. According to the characteristics of the PDC bit that has high ROP and long life in the formation from soft to medium hard, we analyze in this paper the drilling characteristics of the big diameter in deep well, study the mechanism of breaking rock when the bit cuts the rock firstly and reams the hole secondly, and optimize the structure design of the new type PDC reamer, and manufacture a novel reamer （PD6352SFФ311.1×444.5） . The reamer is tested in Ф444.5 mm wellbore of the DB1 Well, and the average rate of penetration of up to 21.68 m/h is increased by 5.2% and 38.0% respectively compared with that of Well Laishen-1 and Well Haoke-1. In addition, its abrasion degree is only 20G when tripped out, which indicates that it can be used longer and thus reduce drilling cost further.
出处
《石油钻探技术》
CAS
北大核心
2006年第3期62-65,共4页
Petroleum Drilling Techniques
